无机盐对磺酸盐型双子表面活性剂溶液表面性能的影响

Effect of Inorganic Salt on the Surface Activity of Sulfonate Gemini Surfactant Solution

在(30±0.2)℃下,用直接观察法、表面张力法和旋转液滴法考察了不同无机盐(NaCl、CaCl2和MgCl2)对磺酸盐型双子表面活性剂DJ溶液溶解性、临界胶束浓度(CMC)值和界面张力的影响。结果表明,磺酸盐型双子表面活性剂DJ具有良好的抗盐性,溶解度可以达到20 000 mg/L以上;在低盐度范围时(小于500 mg/L),随着无机盐质量浓度的增加,表面活性升高,CMC降低;随着阳离子(Na+、Ca2+和Mg2+)价数的增加,CMC降幅增大,且Ca2+的影响程度大于Mg2+;在无机盐质量浓度达到10 000 mg/L时,CMC呈上升趋势;无机盐的加入使溶液界面张力先降后升,然后趋于平稳。无机盐质量浓度在100～1 000 mg/L内,磺酸盐型双子表面活性剂DJ溶液的界面张力可以达到最低。

At （ 30 ＋ 0.2 ）℃, the effect of inorganic salt, NaCl, CaCl2 and MgCl2 on the solubility, CMC （critical micelle concentration） and the interfacial tension of sulfonate Gemini surfactant DJ aqueous solution was investigated by the methods of direct observation, surface tension and rotating droplets. The results show that sulfonate Gemini surfactant DJ had high resistance to salt while its solubility was up to 20 000 mg/L. Within the scope of low salt mass concentration（ less than 500 mg/L）, with the increase of the mass concentration of inorganic salt, the value of CMC decreased while the surface activity intensified. With the increase of the valence of cation （ Na ＋ , Ca2 ＋ and Mg2 ＋）, CMC decreased by a bigger margin, and the influence of Ca2 ＋ was greater than that of Mg2＋. When the mass concentration reached 10 000 mg/L,the CMC value began to increase. The addition of the inorganic salt made the interfacial tension of the solution first decrease and then increase, which gradually lapsed into a smooth level. The low interfacial tension of sulfonate Gemini surfactant DJ appeared within a salinity range of 100- 1 000 mg/L.